Thanks for responding everyone. Doesn't seem like there is a real preference... seems about 50/50 for in front or at the end.
I have a The Elements that I just get a nice bassy (for guitar) overdrive with, and it seems to me like it works best at the front. Then I DO have an excellent overdrive (probably the best I've heard) in my Fender Blues Deluxe. So that probably solves it right there... Elements at the front and amp OD at the end.